| The convergence of data and voice networks in | | | | point, and was found to be easily hacked. The |
| the business environment takes on a new twist | | | | 802.11i standard, adopted as WPA2 (Wireless |
| with the emergence of wireless networking. The | | | | Protected Access), provides for more robust |
| freedom of mobility offered to users in a wireless | | | | security by requiring two way authentication |
| LAN has proven to provide a noticeable boost in | | | | between the user and the network, and uses |
| productivity, efficiency, and. employee morale. No | | | | AES (Advanced Encryption Standard) as its |
| longer is the work force tied to their desk when | | | | encryption engine. |
| on the job. Workers can access company files | | | | As network managers plan the rollout of a |
| and receive important communications from | | | | wireless VoIP network, the greatest security |
| anywhere on the company campus that is in | | | | threat they face is improper implementation. |
| range of a wireless access point. | | | | Building security into the design of the initial |
| With voice communications thrown into the mix, | | | | deployment can, and should affect the network |
| mobile users can stay in touch while roaming the | | | | topology, as well as material costs. Failure to do |
| property inside or out, and even on the road. The | | | | so could lead to further expenses in loss of |
| acceptance of the fixed to mobile convergence | | | | services and network redesigns in the event of |
| concept by the telecommunications industry only | | | | compromise. |
| promises to fuel the fire for the adoption of VoIP | | | | WiFi, VoIP, and the Cellular Networks |
| over WiFi. | | | | Manufacturers of cellular devices are incorporating |
| The Challenges of Implementing VoIP over WiFi | | | | WiFi radios into their handsets at an ever |
| Networks | | | | increasing rate. New versions of mobile operating |
| As with any emerging technology, there are | | | | systems are coming out complete with a built in |
| challenges to overcome. The development of the | | | | VoIP stack, inviting carriers and manufacturers to |
| converged network, i.e. data and voice on the | | | | add VoIP functionality to their devices. Dual and |
| same IP based LAN, while yet to be an | | | | Quad band cell phones can choose between the |
| established norm, is proving to be beneficial for | | | | strongest network available, cellular or WiFi, and |
| businesses from both a cost and productivity | | | | place a call accordingly. |
| perspective. Adding the prospect of VoIP over a | | | | As cell phones become more like mobile offices, |
| wireless network brings up a whole new set of | | | | the benefits of a mobile work force become |
| issues. | | | | apparent. In the case of the road warrior, the |
| VoIP is a time sensitive technology. Calls must be | | | | ability to communicate via email, text messaging, |
| set up and authenticated, and voice packets must | | | | video or voice, allows them to stay on the road |
| arrive at their destination without interruption and | | | | longer without losing touch. In the age of instant |
| on time. This requires a near continuous network | | | | information, mobile office applications allow files to |
| stream, uninterrupted by less sensitive data | | | | be downloaded, edited, and uploaded, increasing |
| transmissions. The implementation of Quality of | | | | the productivity of the traveler to the point |
| Service techniques on wired LANs assure that | | | | where just about anything that can be done in |
| these voice packets receive priority, and call | | | | the office can be done on the road. |
| quality issues such as latency, jitter, and packet | | | | A cell phone that can switch between cellular and |
| loss have been sufficiently addressed. | | | | WiFi networks can significantly reduce |
| Enter the standards based wireless network, a | | | | telecommunications costs at the corporate office. |
| technology in an earlier stage of development, and | | | | With WiFi hotspots popping up at hotels, cafes, |
| more challenges occur. While today's wired | | | | and corporate LANs across the globe, mobile |
| network provides plenty of bandwidth for both | | | | workers can stay in touch with office and family |
| voice and data to coexist, WLANs provide less | | | | both on and off the job. With the addition of a |
| bandwidth, and Quality of Service issues must be | | | | VoIP service provider, cheaper VoIP calls can be |
| revisited. Security measures such as | | | | made from any WiFi network at the push of a |
| authentication and encryption must be | | | | button. |
| implemented and can add to the problem by | | | | Imagine, if you will, a future where one phone, |
| increasing the size of the voice packet. | | | | with one phone number, can seamlessly traverse |
| Additionally, users on the move will traverse | | | | cellular networks, WiFi networks, cable and PSTN |
| wireless access points where handoffs must be | | | | landlines. Where roaming and switching between |
| quick and smooth. | | | | disparate networks occur without interruption or |
| The IEEE 802 standards governing wireless | | | | loss of call quality. Fixed Mobile Convergence is the |
| technology are evolving rapidly and promise to | | | | buzzword of the decade, and the IP Multimedia |
| deal with a broad spectrum of WiFi issues. | | | | Subsystem (IMS) architecture is the standard that |
| Increasing the bandwidth available, prioritizing voice | | | | promises to get us there. |
| packets for QoS, authentication and encryption | | | | The goal of IMS is to provide all the services and |
| protocols for security, and enhanced roaming | | | | applications that the Internet provides, both |
| techniques are all being addressed. | | | | current, and as of yet unimagined. IP based |
| Also in development is the wireless technology | | | | services such as VoIP, Push to talk cellular (POC), |
| commonly known as WiMax, providing for the | | | | videoconferencing, text messaging, community |
| implementation of high bandwidth wireless | | | | services, presence information and file sharing, are |
| communications covering distances of up to 30 | | | | just some of the possibilities. Designed to work |
| miles. The evolution of WiMax could prove of | | | | with any fixed, mobile or wireless packet switched |
| great consequence to developing countries, as | | | | network, backwards compatibility for the legacy |
| well as Metropolitan LANs. | | | | circuit switched phone system is provided through |
| Security in a VoIP/WiFi Network | | | | the use of gateways. |
| Companies wishing to implement wVoIP must | | | | Although still in its infancy, IMS is already being |
| take security issues into consideration from the | | | | implemented by AT&T as the platform in it's |
| start. As in any IP network, the dangers of | | | | newly acquired Cingular cellular network. Interest in |
| hackers, denial of service, highjacking and spam, | | | | investing in a new infrastructure by mobile and |
| all lurk in the shadows. | | | | fixed operators has been up and down, as they |
| Because a wireless network uses radio | | | | weigh the costs and benefits of the new |
| frequencies as its transmission media, the security | | | | technology. |
| normally provided by a firewall in a wired network | | | | As the technology of VoIP over WiFi networks |
| is not sufficient, simply because of the physics. | | | | continues to develop, businesses of all sizes can |
| Whereas to break into a wired LAN requires | | | | reap the benefits of increased mobility, |
| hackers to either physically be inside the network | | | | productivity, and significant cost savings. |
| or to hack in through the Internet, in a WLAN | | | | Standards committees are constantly working on |
| they can grab network transmissions from the air | | | | ways to increase security and quality of service, |
| while parked across the street. The security | | | | and as fixed mobile convergence gains |
| issues that network managers must consider in a | | | | acceptance in the telecommunications industry, |
| VoWLAN are the privacy of conversations, and | | | | more choices in the services offered and the IP |
| the protection of the network infrastructure. | | | | applications available to businesses are sure to |
| For WiFi networks, security has had a shaky start | | | | follow. What will also be interesting to watch, is |
| with the implementation of WEP as its security | | | | how these very bandwidth intensive applications |
| mechanism. WEP provides for authentication and | | | | will be priced by the carrier networks, and how it |
| encryption between the user and the access | | | | will affect the neutrality of the Internet. |